Stady On Treatment Of Wastewater Contaminated By Ni,Co,Cu From JinChuan NO.2 Metallurgy Plant

Nowadays environment protection has been a focus, especially in water pollution. In this paper, wastewater drained by NO.2 Metallurgy Plant, JinChuan Inc., is involved, which is a complex system included heavy metal, such as nickle, cobalt, copper, etc., electrolyte and ligands.The first step of this paper is to given a melody calculation. The calculation includes four systems, which named Me( II )-H2O, Me(II)-HN:-H2O, Me( II )-S2--H2O, and Me( II )-HN3-S2--H2O. Through the calculation, the minimums of residual concentration and its pH, and ranges of pH value when the residual concentration is less than 1 mg/L, are given. And these can help to choose the parameters' level and forecast the results of experiments. As for the coagulation, the reason of the requirement to pH at 9.50 other than 8.80 is that the coordination copounds of Ni( SO42- ) appear, which increase the residual nickel concentration. And the function of coagulator is proved by sweep-floe coagulation. As for the sulfide precipitation-coagulation, the function of coagulator is proved by both sweep-floe coagulation and charge neutralization.Secondly, experiments are investigated in the base of current process. The results show the cost of PFS, PAM can decrease to Fe/Me=1 and 2 mg/L respectively, while it's invalid to decrease pH value in order to decrease the cost of production. The further research show, complex reagents (mixed by PFS and PAC according to Fe/Al=1) can enhance the effect of treatment and decrease cost of production, which are manifested by industrial experiments. In industrial experiments, the parameters are set as Fe/Ni=0.25~0.5 and cost of PAM 4 mg/L above pH 9.50, then the residual concentration of Ni, Co, Cu can decrease to 0.57, 0.12, 0.04 mg/L respectively, and the cost of production is 0.229 yuan/m3, which is lower dramatically than that in 2001 year. What's more, the effect of treatment is worse when the wastewater included cobalt and ammonia (WCA) pipe into the current wastewater. Though it is feasible to treat by sulfide precipitation when WCA piped, yet it is advisable to separate WCA from current wastewater in all round.Finally, the treatment of WCA is investigated. Some results can concluded. The value of pH should be less than 8.0 in the view of low production cost. In the aspect of treatment, it is recommendable to adopt the proces of one waste treated by other waste (OWTOW). The proces of OWTOW is characterized by sulfide precipitation-coagulation, which can decrease the cost of production and enhance the effect of treatment. In the proces of OWTOW, the descend order affected the residual cobalt concentration is cost of Na2S, cost of PFS, and pH respectively, and the optimum level are Na2S 0.073 g/L, Fe/Me=2:1 at pH 7.0.